The present invention makes it possible to improve the alignment accuracy of the joint section of an ink cartridge with an ink supply route of an inkjet head. Based on this, the present invention provides an ink cartridge capable of preventing ink leakage with high reliability and constructed inexpensively in a reduced size and particularly suitable for a pit-in system. To attain this, distance (L1) is set to be shorter than distance (L2), where the distance (L1) is the one between a joint section (145) positioned in the proximity of a front surface (1A) of an ink cartridge (1) and an engage reference portion (135) serving as a reference position when the ink cartridge (1) is installed in the inkjet printing apparatus; and the distance (L2) is the one between the front surface (1A) of the ink cartridge (1) and the engage reference portion (135).
